#ifndef _RECTANGLE_H_
#define _RECTANGLE_H_

class Rectangle  
{
public :
  Rectangle(double len, double width);
  double getArea(void) const;
  double getPerimeter(void) const;
  void changeShape(double len, double width);

private :
  double length_m;
  double width_m;

private :
  bool valid(void) const;
  bool checkNewShape(double& len, double& width) const;  
};

#endif

